From: mharris AT blackwidow DOT saultc DOT on DOT ca Date: Mon, 10 Feb 1997 07:51:16 -0500 (EST) Reply-To: mharris AT blackwidow DOT saultc DOT on DOT ca To: Roger Ivie cc: OPENDOS AT mail DOT tacoma DOT net Subject: Re: [opendos] COMMAND.COM enhancement In-Reply-To: <01IF34DWTGTE8ZOP0K@cc.usu.edu> Message-ID: Organization: Total disorganization. MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-opendos AT mail DOT tacoma DOT net Precedence: bulk On Thu, 6 Feb 1997, Roger Ivie wrote: > OK, I've been thinking about it and I finally have my objections to modifying > COMMAND.COM so that it does direct screen writes down to a few simple > statements. Here goes: > > Why is it that when we're speaking of Linux, it's A Good Thing to have > device independence, yet when we're speaking of DOS it's suddenly A Good Thing > for every program to lug around half a dozen video drivers? In any OS, it is desirable to have device independance. That includes Linux AND DOS. However, I have programs for DOS, AND for Linux that do DIRECT screen writes, and also access other hardware *directly*. Who said it was a good thing to have a half a dozen video drivers for programs in DOS? I never heard anyone say that. > If you want to improve the performance of OpenDOS screen writes, put the > improvement where it belongs: in the console device driver. I don't want to improve the performance of OpenDOS screen writes. I want to improve the performance of COMMAND.COM screen writes. Since programming COMMAND.COM with a few condition tests can easily provide direct screen writes, it is the only choice. I'm sure that the DOS console device driver is allready written to be quite optimized. Regardless of how much you optimize the console driver, it's not going to compete with direct video access at the application level. A program calling DOS to do I/O with the display goes through MANY layers of code before arriving at video memory. This includes many interrupt calls which include a TONNE of stack push/pop work. You are just not getting the picture. You just want to continue arguing just to see your name in print. Mike A. Harris | http://blackwidow.saultc.on.ca/~mharris Computer Consultant | My webpage has moved and my address has changed. My dynamic address: http://blackwidow.saultc.on.ca/~mharris/ip-address.html mailto:mharris AT blackwidow DOT saultc DOT on DOT ca DJGPP: Current version 2.01